The names are hopefully obvious enough not to have to explain what each class is. See their pages for more details.

To save some confusion, it's worth pointing out here that qr// is not a regular expression (which PPI takes to mean something that will actually examine or modify a string), but rather a quote-like operator that acts as a constructor for compiled Regexp objects.

The get_delimiters method returns the delimiters of the regexp as an array. The first element is the delimiters of the match string, and the second element (if any) is the delimiters of the substitute string (if any).